Generally, a user of a toilet does not habitually raise a toilet seat after the use of the toilet seat, and thus the toilet seat tends to be polluted or fouled by a next male user when he urinates into the toilet. There are many known apparatuses or devices made in the art to solve such a problem by providing an auto-rising toilet seat.
Generally, conventional apparatuses or devices for automatically raising a toilet seat can be classified into the following categories;
1. Spring type: an apparatus of such a type mainly makes use of resilience of springs to raise a toilet seat when a user left away from the toilet seat. For example, ROC Patent Application No. 76208424 (Publication No. 104742) is related to an apparatus for automatically raising a toilet seat of such a spring type. However, the operation of an apparatus of such a spring type very likely gets worse due to the deterioration of resilience or fatigue of the springs used therein. Besides, it is inconvenient, uncomfortable and dangerous to a user, especially to an old person, child or invalid user, because the user has to press the seat before he/she sits on the seat or until he/she left away the seat in preventing the toilet seat from moving with the hip of the user. PA1 2. Lifting weight type: an apparatus for automatically lifting a toilet seat of such a type mainly provides a lifting weight around pivot shafts in association with connecting rods and wires to create a rotational torque against the torque created by the weight of the seat, so as to complete the purpose for automatically lifting the toilet seat when a user left away from the seat. For example, ROC Patent Application No. 75212373 (Publication No. 96211) disclosed a delayed auto-rising toilet seat of such a lifting weight type. However, since the use of such a type need an additional space to allow the rotation of the lifting weight which extends from the seat, it is bulky and inconvenient to installation. Besides, when a user is leaving away from the toilet seat of such a type, the toilet seat moves upwardly together with the hip of the user, and cause an uncomfortable feeling to the user. Especially, it is dangerous to an old person, children or an invalid users.
In conclusion, various type of conventional toilet seat to be automatically lifted bears many disadvantages, e.g., the seat failing to be maintained in a horizontal position before the user already left away the seat and causing a trouble to the user.